Characterisation of a micro-pressure filtration and cleaning system under sandy and brackish water conditions

To investigate the hydraulic effects and performance of the micro-pressure filtration and cleaning tank under conditions with sandy and brackish water, physical model tests were conducted with five groups of flow rates (6–14 m³ h⁻¹), four groups of sediment contents (0.5–2.0 g l⁻¹), five groups of mineralisation degrees (0–5.0 g l⁻¹), and three groups of screen apertures (0.125, 0.150, and 0.180 mm). Dimensional analysis, multiple linear regression analysis, and the non-dominated sorting genetic algorithm II (NSGA-II) were used to analyse the test results. The results showed that the optimal operating conditions of the micro-pressure filtration and cleaning tank under the scope of this test were a screen aperture of 0.175 mm, a flow rate of 13 m³ h⁻¹, a sediment content of 1.8 g l⁻¹, and a mineralisation degree of 4.7 g l⁻¹. The micro-pressure filtration and cleaning tank was intermittently discharged and rinsed, the discharge time was 30–40 s, and the flow rate of discharge and rinsing was 5.54 m³ h⁻¹. Prediction models of the head loss and the filtration efficiency of the filter were established. The coefficients of determination (R²) were greater than 0.9, the average relative errors of the predicted and measured values were 2.98% and 2.17%, respectively, and the corresponding root mean square errors were 0.0549 m and 0.642. The research results can be used as a reference for in-depth investigations on the performance of the micro-pressure filtration equipment in front of pumps.